British light heavyweight Buatsi secured a victory yet underwhelming start to life under fresh promotional backing with a points victory over Zach Parker in the Manchester arena.
The Olympic bronze medallist's work rate appeared to earn him a split decision in a competitive 10-round fight at the Co-op Live Arena.
But Parker landed significant shots, delivering effective single shots in a match where the approaches didn't complement each other, with frequent clinching disrupting the contest.
The officials judged it 96-94 to Buatsi, with the final judge a even score.
"It wasn't my best performance but how do champions respond? They prevail," the victor said in the arena as he was met by disapproval from the spectators.
The British fighter returned to winning ways after his first professional defeat - an memorable fight with his previous opponent in last winter - to secure a 20th pro success.
Various analysts believed the challenger, thirty-one, should have been awarded the decision but the contender endured the second setback of his 28-bout career.
The Champion Secures Win in Dull Match
The fighter's advancement has plateaued in the past few years through promotional disputes and long spells of inactivity.
Earlier forecast as the rising talent of British boxing, he now finds himself trying to achieve expectations - perhaps in what seems like a last chance - under new promotional backing.
He opened tentatively, with neither fighter ready to be aggressive in a cagey opening few rounds.
Parker, whose sole prior loss came at super middleweight against John Ryder in 2022 after breaking his hand mid-fight, was competing in only his second bout at the higher weight class.
By the fight's midpoint, Parker had kept it close, creating difficulties for Buatsi, who utilized a protective stance to narrowly win the cleaner periods.
The crowd's patience diminished during frequent holding, with Parker slipping to the canvas several times during grappling.
Parker closed well, but multiple periods were hard to judge. Nevertheless, ex-champion Carl Frampton - working with the broadcast network - had it strongly leaning for Parker, scoring for Buatsi just a single round.
Buatsi progresses, but with the presence of heavy hitter David Benavidez, and Eastern European fighter Dmitry Bivol ruling the division, the road to world glory - judging by this showing - still seems difficult.
Hatton Tribute Inspires All-Manchester Battle
In the secondary fight, Lyndon Arthur defeated Bradley Rea by divided decision in a excellent Manchester vs Manchester contest to secure the European light heavyweight championship.
The stadium became quiet for a profoundly moving tribute prior to the bout as a bell ceremony rang in honor of Manchester's own Hatton, who died 46 years old in recently.
It was the premier televised boxing event in the urban center since Hatton's death. As the last bell disappeared, the silence gave way to a roar of "only one Hatton".
The competition during the bout reflected the sentiment. Arthur was knocked down by a left hook directly to the face in the initial stage, standing uncertainly to his feet on the referee's count.
But the red-colored shorts of Arthur soon came forward again. From the other corner, Rea - in opposing blue - was injured soon, noticeable damage forming under his orbital area as the pair traded hard punches.
Rea, twenty-seven, landed power punches but the champion, 34, matched the intensity with stinging uppercuts as the intensity rarely dropped over the full distance.
Arthur narrowly won the verdict with official scores of 114-114, narrow lead and clearer margin, but both fighters were persistent and brave, everything their hero Hatton represented.
